1. Field of the Invention
The present application relates to a novel manufacture method for a blazed concave grating, which can be widely applied to the fields such as optical spectrum instruments, and analysis and measurement, and belongs to the technical field of grating manufacture.
2. Related Arts
A holographic concave grating, which integrates dispersion, focusing and a flat field (where an important characteristic of the concave grating is imaging, and it is capable of imaging in a plane, and therefore, a CCD can be used as a receiving device), is a key element in a portable grating optical spectrum instrument and directly decides the final quality of the optical spectrum instrument. Due to the restriction of a geometric shape of a concave substrate, it is difficult, even impossible in many cases, to directly etch a concave grating by using ion beams. Consequently, a groove profile of the concave grating cannot be precisely controlled, and it has been difficult to improve the diffraction efficiency, leading to an application bottleneck of the concave grating.
For this problem, a common method at present is to directly manufacture a convex master grating by means of exposure and then obtain a concave grating by means of replication. Because flat-field concave gratings have uniform groove profiles, after being replicated by using the convex master grating, a flat-field concave grating only needs to be pulled along the vertical direction, to obtain a required concave gating. However, due to a blazed angle, if a blazed concave grating is also pulled along the vertical direction, the diffraction efficiency of the grating is greatly affected, and the application of the grating is limited.